Sara McColgan/Warner Bros. RecordsNorwegian duo Nico & Vinz released their U.S. debut album Black Star Elephant -- featuring the global smash "Am I Wrong" -- a year ago, and while they work on their new album, they're giving fans something to tide them over. It's a new EP called Cornerstone, out today, and the guys say the songs are "displaying more sides of us."

"We just wanted to put something out, because it’s been a while and we wanna perform with new songs, we wanna give new songs to our fans," Nico says, explaining why they wanted to release an EP now. "I don’t think there’s a deeper meaning behind it than just wanting to put something out and the album isn’t ready yet. So we’re gonna put out four songs and people will hear some new stuff."

Explaining why the EP is called Cornerstone, Vinz says, "We feel like we’re really excited about the music and we feel like this actually might be the cornerstone in our career, in our, especially in our growth. So, [we're] excited about giving this to the people and displaying more sides of us than we had done earlier."

While the EP features a number of mellow love songs, the duo's current single "That's How You Know" is definitely a different side of Nico & Vinz: it's a humorous ditty whose uncensored chorus goes, "That's how you know you f***** up." Since "Am I Wrong" was such a serious song, did this new track shock their fans?

"Some, maybe. But then again, no," Nico says. "Because if you followed us and [had] seen us in our interviews and stuff, you’ll see that we also have that humorous side, so even if the music in 'Am I Wrong' and our previous album had more deeper messaging, we’re still humorous guys also...so, I don’t think people were too surprised. I think they were positively surprised."

As for the continuing popularity of "Am I Wrong," the duo says they've only now been able to sit down and realize just how massive that song was. "We’re still really mindblown about what we’ve been able to do this last year," says Nico. Vinz adds, "We had a number one song on the radio in the U.S. and I didn’t understand what that meant at that time....now, when I sit in the car and I listen to the radio and I hear the same song being played -- like, the number one song -- I’m like, 'They played our song that much?' Like, it must have been huge!"

"Am I Wrong" also got Nico & Vinz an invite to the most coveted gig in town: a guest slot on Taylor Swift's 1989 tour. The duo joined Taylor onstage at one of her Canadian shows to perform the song with her and Nico says that T-Swift was "super, super cool."

"She was really hands-on with her show -- she had everything under control and treated us really good," Nico adds. "We felt almost like her two little brothers. And the show was amazing -- a stadium show with 40,000 Canadian kids -- and we couldn’t even hear ourselves ‘cause it was just so much screaming, you know?"